The present invention relates to a treatment and observation apparatus using a scanning probe. As such an apparatus, there is known an apparatus utilizing a focused ion beam to observe and treat or work a semiconductor device.
An apparatus of this type using the focused ion beam as a probe is described in, for example, Solid State Technology, pp. 77-78, (May/1987). The apparatus uses secondary electrons obtained upon irradiation of the ion beam on a sample to form an image of the sample. A sample area to be treated is designated on a display screen on which the image is displayed. The area to be treated is irradiated with an ion beam under conditions different from an observation mode and is treated in accordance with a purpose.
In the apparatus, one point on the sample designated by an address is irradiated with the ion beam constituting a probe. When the address is changed, the ion beam is directed to a point designated by the changed address to irradiate the point with the ion beam. An address of a pixel on a display screen on which an image to be observed is displayed is in one-to-one correspondence to the address specifying the irradiation point of the probe on the sample.
In the treatment mode, the area to be treated is designated on the display screen on which the observation image is displayed as described above, and the address of the pixel on the display screen corresponds to the address on the sample. Accordingly, the designation accuracy of the area to be treated depends on the resolution of the display screen on which the observation image is displayed. In other words, a unit of a pixel on the display screen is a minimum unit for designating the area to be treated. Accordingly, the treatment accuracy is specified by a magnification of the observed image. In this connection, as a space or gap between two adjacent points designated by addresses on the sample becomes smaller, the magnification upon observation becomes larger and the treatment accuracy becomes higher.
In the conventional apparatus, since a larger area to be treated is designated by using the observed image having a low magnification, the treatment accuracy can be ensured.